It is known to use automatic palletizing equipment, i.e., automatic palletizers, in conjunction with envelope manufacturing machines. In this process, the finished envelopes discharged at the end of the envelope manufacturing machine are first supplied to an automatic packaging device, an automatic packer, which deposits a given quantity of envelopes in a packaging box and packs them therein in a manner secure for transport. The automatic packer is followed by an automatic palletizer including a palletizing robot and a device for changing the pallets. The palletizing robot accepts the packaging boxes coming from the automatic packer and arranges them in a space-saving manner suitable for transport on a pallet that is prepared at a loading station provided for that purpose.
As soon as a pallet is completely filled with packaging boxes, it must be replaced by an empty pallet in order to be able to continue the palletizing process. Devices for changing pallets are known which transport the loaded pallet via a fixedly installed, conventional roller and/or chain conveyor from the loading station to a collection station, from which the pallet may be collected by a forklift, for example. Moreover, the known devices have a supply station, from which an empty pallet may be supplied, also via a fixedly installed, conventional roller and/or chain conveyor.
The known devices having roller and/or chain conveyors for changing the pallets have two essential disadvantages. Firstly, they have a relatively substantial space requirement since the roller and/or chain conveyors must be fixedly installed at the supply station, the loading station, and the collection station. This leads to space problems particularly when the space behind the envelope manufacturing machine is limited and/or a plurality of envelope manufacturing machines are set up next to one another and the passage between the machines must be just wide enough to allow operating and maintenance work to be performed appropriately at the machine. The width of the passage required for this is typically smaller than the width to be provided when a collection station or a supply station having conventional roller and/or chain conveyor equipment is to be provided between two neighboring machines. Secondly, in the case of the known devices, the palletizing process must also be interrupted for an unacceptably long time in order to change the palettes, both to convey full pallets from the loading station to the collection station and also for conveying the empty palette from the supply station to the loading station, which can only take place subsequently.